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UNITED STATES PATENT;

CHARLES. BROWN, OF BOSTON, MASSACHUSETTS; ASSIGNOR' TO'GEO. W.BANKEILAND GEO. O. CARPENTER.

PAINT-MILL.

To all w 750m it may, concern...

Beit known that I}, OHARLns' W. BRowN, of? Boston, in. the county ofSuifolk: and State of Massachusetts, have invented certain. new and;useful. Improvements in Mills for Grinding Paint an a other Moist,Substances; and. I do.hereby declare that the following is a. full,clear, and exact description. of thesame, reference being had to theaccompanying drawings, forming part. of this specification, in whichFigure. 1,.is an elevation of. a-paint mill, having my improvements,Fig. 2,.isa vertical. section of the samewtaken nearlyat right angles toFig. 1, but showsthe runner and spindle entire... Fig, 3, is a plan ofthe same. Fig,. 4c, is a. top view of the. lower stone. Fig. 5, is-an.elevation of thescra'per and: guardl withz a. section of-a portion ofthe trough, which. receives the ground paint.

Similar letters of, reference indicate-corresponding parts in theseveral figures.

The mill. which forms-the subject. of these improvements, consists oftwo: horizontal stones, of which the lower stone is therunner, andzissecured firmly tothe spindle, and the top stone is suspended above it. p

My first improvement consists in attaching the trough which receives theground paint or material as it leaves the stones, to the running stoneso that it may rotate therewith. The attachment of this trough to therunning stone obviates thegreat difiiculty experienced in paint millswhose lower stone is the runner, of keeping the paint from running overthe sides of the stone,

and setting between the stone and the curb surrounding it, where it soonmakes a hard bed which produces great friction on the runner.

My second improvement consists in combining with the rotating painttrough, a fixed scraper and guards to cause the paint to flow over andout of said trough and into any suitable receptacle as will bedescribed. To enable those skilled in the art tomake and use myinvention, I will proceed to describe its construction and operation.

A, is a bed plate, upon and some distance above which, is supported bypillars B, B, a circular table C, of cast iron, upon opposite sides ofwhich are erected two standards D, D. These standards receive and formguides for two vertical sliding rods, a, a, the lower parts of which arescrewed and 12,431,. dated. February 20, 1855.

pass easily throughthe; table; (3,. above and below which they. arefurnished: with nuts 71,6, by which they can. be adjusted and securedat'va rious: elevations. The-rods a, a, contain.- the bearingsto:receive the journals of two pivots b, b', which are attached diin thesame manner? as; the m'ariners; com:

pass, and is free. to oscillate,- to a. limited.

extent, in any direction.

In order to, provide:- fon' a. considerable variation: in the.elevation: of the stone, 1 make in the rods (1,, a,-; several. bearingse, e, to receive the journals of the; pivots b, b.

The lower stone or runner'F,, rests. upon,

and issecuredi tov a1 flange f, on: the: spindle G, and stands a short.distance above the table G. The bottom of the spindle rests in: a step.bearing 9,, on the bed plate A, and works in aguide box It, secured tothe table (3.. The height-of the-stone F, is fixed, and the faces of thestonesare adjusted; at.

th. proper distances apart, to; grind to the required. degree offineness, by raising or lowering the rods a, a,.asmaybenecessary,

by means of the nuts 71, z. The suspension of the top stone by theadjustable rods a, a, enables another important duty to be performed inaddition to the adjustment ofthe stones to grind at any desired degreeof fineness, viz: the raising of the upper stone to admit air betweenthe faces of the stones to cool them off quickly when they becomeheated, as they sometimes unavoidably will, during the grinding process.In grinding paint, this is very important, as the heating of the stonesis highly injurious, if the grinding be continued, and to some kinds ofpaint, would be almost entirely destructive; and if no facility wereaflorded for admitting air freely between the stones, the grindingoperation would require tobe stopped a long time to enable them to coolevery time they became heated, and much delay would be the consequence,but when the stones are separated to some distance apart, and plenty ofair allowed to circulate between them, the time occupied in cooling willbe short.

H, is the adjustable hopper, by which the paint mass is supplied to themill stones to be ground. The throat j, of the hopper is of a depth alittle greater than the thickness of the top stone, to the opening oreye, in the center of which it fits easily. A flange la, extends allaround outside the top of the throat of the hopper, and in this flangeare cut a number of female screws to receive a corresponding number ofmale screws Z, Z, which rest upon the top stone, and support the hopper.By turning the screws Z, Z, the hopper can be raised or lowered toincrease or diminish the space between its bottom edges and the face ofthe runner F, and thus regulate the feed; or by allowing the hopper tocome right down on the stone, the feed may be entirely stopped.

m, m, are the spiral blade feeders, such as are frequently attached tothe sides of mill spindles, for the purpose of forcing the mass betweenthe stones. Above these feeders m, m, is a spiral or twisted blade :11,which is soured to the top of the mill spindle and a little eccentricthereto. This feeder extends nearly, or quite, to the top of the hopper,and feeds the mass gradually down the hopper, and at the same time,opens the mass to admit air into and among it, which is very desirable.

N, is the trough which surrounds the lower stone, and receives theground paint. Its bottom is nearly level with the top of the sides ofthe lower stone; and it is fitted closely to the stone all around andfirmly secured, so that no paint can escape except at the proper pointof discharge where it receives a fixed oblique scraper 0, which issecured to a fixed standard p, erected on the table C. This scraper fitsto the interior of the trough, and nearly close to the side of thestone. To the same standard 79, are atrepresented in the drawing, forthe purpose of preventing it from being thrown off by centrifugal force,as it is caused by the action of the scraper 0, to flow over the trough,and both serving to conduct it downwards to a spout to, cast on one sideof the table C, down which it passes to any suitable receptable.

The mill spindle receives motion by level gearing from a horizontaldriving shaft P.

What I claim as my invention, and desire to secure by Letters Patent, is

1. Attaching the trough N, which receives the ground paint or material,to the running stone F, so that it may rotate therewith, for the purposeof obviating the ditficulty experienced in paint mills whose lower stoneis the runner, of keeping the paint from running over the sides of thestone, and setting between the stone and the curb surrounding it, where.it soon makes a hard bed which produces great friction as set forth.

2. In combining with a paint trough rotating with the runner, a fixedscraper 0, and guards g, and r, to cause the paint to flow over and outof said trough, and be guided into any suitable receptacle, while themill continues to run, substantially as described.

CHARLES W. BROWN. Witnesses:

O. D. MUNN,

J. W. HAMILTON.

